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#include<cstdio>
#include<cstring>
#include<algorithm>
#include<iostream>
#include<queue>
#include<map>
#include<stack>
#include<cmath>
#include<set>
#include<bitset>
#include<complex>
#include<cstdlib>
#include<assert.h>
#define inc(i,l,r) for(int i=l;i<=r;i++)
#define dec(i,l,r) for(int i=l;i>=r;i--)
#define link(x) for(edge *j=h[x];j;j=j->next)
#define mem(a) memset(a,0,sizeof(a))
#define mid (x+y>>1)
#define ll long long
#define eps 1e-8
#define succ(x) (1<<x)
#define lowbit(x) (x&(-x))
#define sqr(x) ((x)*(x))
#define NM 100005
#define nm 10005
using namespace std;
const double pi=acos(-1);
const ll inf=1e9+7;
ll read(){
ll x=0,f=1;char ch=getchar();
while(!isdigit(ch)){if(ch=='-')f=-1;ch=getchar();}
while(isdigit(ch))x=x*10+ch-'0',ch=getchar();
return f*x;
}
int n,k;
ll s,ans;
ll qpow(ll x,ll t){return t?qpow(sqr(x)%inf,t>>1)*(t&1?x:1ll)%inf:1ll;}
int main(){
int _=read();while(_--){
n=read();k=read();s=0;
if(n>=2)
inc(i,1,k)inc(j,1,k)s+=qpow(i-1,2*(n-2))*qpow(j-1,2*(n-2))%inf*sqr(min(i-1,j-1))%inf,s%=inf;
ans=s*sqr(n)%inf*sqr(n-1)%inf*qpow(k,sqr(n-2))%inf;
s=0;
inc(i,1,k)s+=qpow(i-1,2*(n-1)),s%=inf;
s=s*qpow(k,sqr(n-1))%inf*sqr(n)%inf;
ans+=s;ans%=inf;
printf("%lld\n",ans);
}
return 0;
}
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